<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="leaveIndex" @mouseenter="enterShow">
        <h2 class="all">全部商品分类</h2>
      <div class="sort" v-show="show"  >
        <div class="all-sort-list2" @click="goSearch">
          <!-- 一级分类 -->
          <div :class="{changeColor:InitialValue==index}" class="item" v-for="(category,index) in categoryList" :key="category.categoryId" @mouseenter="changeIndex(index)">
            <h3>
              <a :data-categoryName="category.categoryName" :data-category1Id="category.categoryId" >{{category.categoryName}}</a>
            </h3>
            <!-- 二、三级分类 -->
            <div class="item-list clearfix" :style="{display:InitialValue==index?'block':'none'}">
              <div class="subitem">
                <dl class="fore" v-for="categoryChild in category.categoryChild" :key="categoryChild.categoryId">
                  <dt >
                    <a :data-categoryName="categoryChild.categoryName" :data-category2Id="categoryChild.categoryId">{{categoryChild.categoryName}}</a>
                  </dt>
                  <dd>
                    <em v-for="categoryGrandson in categoryChild.categoryChild" :key="categoryGrandson.categoryId">
                      <a :data-categoryName="categoryGrandson.categoryName" :data-category3Id="categoryGrandson.categoryId">{{categoryGrandson.categoryName}}</a>
                    </em>
                  </dd>
                </dl>
              </div>
            </div>
          </div>

        </div>
      </div>
      </div>
       <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>

</template>

<script>
import { mapState } from 'vuex'
//按需引入节流依赖
import throttle from 'lodash/throttle'


export default {
  name: "TypeNav",
  data(){
    return {
      InitialValue:-1,
      show:true
    }
  },
  mounted(){
  
    //设置三级联动的显示和隐藏
    if(this.$route.path !="/home"){
      this.show = false
    }
  },
  computed:{
      ...mapState("home",['categoryList'])
  },
  methods:{
    //改变索引值并设置节流。  
    changeIndex:throttle(function(index){
        this.InitialValue = index
    },50),
    //鼠标离开后，索引值置为-1
    leaveIndex(){
        this.InitialValue = -1
        if(this.$route.path !='/home'){
          this.show = false
        }
    },
    //控制三级联动显示
    enterShow(){
      if(this.$route.path !='/home'){
          this.show = true
        }
    },
    //设置三级联动的编程式导航，进行路由跳转并传参
    goSearch(e){
        const element = e.target
        //获取data自定义属性。
        const {categoryname,category1id,category2id,category3id} = element.dataset
        if(categoryname) {
           this.show = false
          let location = {name:"search"}
          let query = {categoryName:categoryname}
          if(category1id) {
            query.category1Id = category1id
          }else if(category2id) {
            query.category2Id = category2id
          }else if(category3id) {
             query.category3Id = category3id
          }
          //合并传参
         if(this.$route.params) {
          location.params = this.$route.params
           //整理query参数
          location.query = query
          //进行路由跳转
          this.$router.push(location)
         }
        }
    }
  }
}
</script>

<style scoped lang="less">
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 480px;
      position: absolute;
      background: #fafafa;
      z-index: 999;
      .all-sort-list2 {
        .changeColor{
          background-color: skyblue;
        }
        .item {
         
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }


        }
      }
    }
/*     //过渡动画的样式
    .sort-enter,.sort-leave-to{
        height: 0px;
    }
    .sort-enter-to,.sort-leave{ 
        height: 480px;
    }
    .sort-enter-active,.sort-leave-active{
      transition: all .3s linear;
    } */
  }
}
</style>